DISCLAIMER; This is a working document provided by the Centers for Disease Control and Prevention (CDC) 

technical support contractor, SC&A, for use in discussions with the National Institute for Occupational Safety and 

Health (NIOSH) and the Advisory Board on Radiation and Worker Health (ABRWH), including its Working Groups 

or Subcommittees. Documents produced by SC&A, such as memorandum, white paper, draft or working documents 

are not final NIOSH or ABRWH products or positions, unless specifically marked as such. This document prepared 

by SC&A represents its preliminary evaluation on technical issues.

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution.

MEMORANDUM

TO: Savannah River Site Work Group 

FROM: SC&A, Inc.

DATE: April 26, 2018 

SUBJECT: SC&A Comments on NIOSH Draft Permit Sampling Plan 

SC&A reviewed the National Institute for Occupational Safety and Health’s (NIOSH’s) draft 

“SRS Work Permit Sampling Plan” that was distributed by Tim Taulbee’s email of April 17, 

2018, subject SRS Work Permit Evaluation – Path Forward. Our comments are provided below, 

in advance of the scheduled May 8, 2018, Savannah River Site (SRS) Work Group conference 

call on this subject. We welcome any clarification from NIOSH on these points prior to the 

conference call.

General

A critical aspect of any valid coworker model development is establishing the crucial link 

between the exposure potential of the monitored and unmonitored subpopulations. In essence, it 

must be adequately demonstrated that the exposures experienced by the monitored workers are 

representative of the exposures experienced by the unmonitored workers. Alternatively, if it is 

determined that some portion of the unmonitored worker population was performing work in a 

different radiological environment then it would likely be inappropriate to apply coworker doses 

to that subpopulation. 

To establish this necessary representative link, NIOSH proposes to compare bioassay data 

associated with work permits for monitored construction trade workers (CTWs) and unmonitored 

subcontractor construction trade workers (subCTWs) to ascertain whether these two groups 

“worked side by side in the same radiological environment at the same time.” NIOSH will 

“randomly pull” Safe Work Permits (SWPs), Job Plans, and Radiation Work Permits (RWPs) for 

this purpose and “directly compare the monitoring of subcontractor workers listed as having 

worked on the individual Work Permit.” 

SC&A Comment 

The key objective of this sampling should be to demonstrate that (1) the radionuclides to which 

workers were potentially exposed are the same and (2) the actual work, and exposure potential of 

that work, were the same. For the second objective, some knowledge or characterization of the 

permitted work would be necessary. If the sampling shows the work of two groups not to be the 

same, then NIOSH would need to demonstrate for (1) that the target radionuclides that are not 

the same (for subCTWs) would have negligible significance to exposure or could be bounded by 
Memo – Comments on Draft Permit Sampling Plan 2 SC&A – April 26, 2018 

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

other means, and for (2) that the subCTW work or exposure potential in question could be 

bounded by other means. However, to demonstrate that the planned permit sampling achieves 

these objectives, the draft sampling plan needs a clear statement of outcome metrics, i.e., what 

the specific end results are envisioned to be and how success will be defined for these results. 

For example, by what measure (qualitative and quantitative) will the comparability of the two 

worker populations (CTW vs. subCTW) be determined? 

Specific

1. SC&A recommends that the Standing Radiation Work Permit (SRWP) not be included in 

the sampling for the reasons cited (typifies more routine work). SC&A is unclear on the 

status of “Extended Special Work Permits (EWPs)” and would not want those included if, 

by their extended timeframe, they were more typical of routine work (as with the 

SRWPs).

2. SC&A agrees that the potential dose related to tritium exposure at SRS during the 1990s 

was not significant and can be bounded by a large quantity of routine bioassay data; we 

recommend that permits for tritium exposures not be sampled. (However, tritium 

exposures before reactor shutdown, while unlikely, may have been higher before 1989 

and may be problematic if job-specific bioassays were missed—see 2017, 

page 23).

3. SC&A agrees that in vivo monitoring should be included but treated with a degree of 

caution, in that permit target radionuclides need to be accounted for in the periodic 

(e.g., annual) in vivo monitoring performed. 

4. SC&A has a concern about the status of pre-1989 sampling. In his email forwarding 

NIOSH’s proposed permit sampling plan for SRS, Tim Taulbee indicates that, based on a 

survey of Radiation Survey Logsheets during the 1970s and 1980s, the number of surveys 

for DuPont in-house maintenance greatly exceeded that of subcontractor work. The 

implication seems to be that this would make a sampling comparison for the DuPont 

operational era unnecessary. SC&A disagrees for reasons stated in the attachment to this 

memo.

5. NIOSH states the following in the introduction: 

The numerical summary contained herein also includes the fact that 

NIOSH and the ORAU Team continued to work with the site Records 

Management department during the March 2018 site visit to determine if 

additional target boxes may exist and be available for review. 

It is not clear if the effort to locate additional target records is still ongoing or the 

available records have been exhausted. Location of additional target records would be 

especially critical given the limitations in records identified for the pre-1989 period.
Memo – Comments on Draft Permit Sampling Plan 3 SC&A – April 26, 2018 

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

6. In the section “Execution of the Sampling Plan,” NIOSH states: 

Before the site visit, the statistician will pick a stratum (area will be 

chosen so that the areas sampled are proportional to the areas in the 

sampling frame) and randomly choose an available year from that area. 

It is not clear whether this means that each site area (with the possible exception of the 

reactor areas) will be given equal weight for the purposes of sampling or if areas with a 

larger number of identified folders will be given greater weight (e.g., F and H Areas).

7. In the section, “Execution of the Sampling Plan,” NIOSH states: 

ORAUT will capture all available bioassay for each of the identified 

CTW’s, regardless of sample dates. Finally, ORAUT will evaluate the 

bioassay data and provide a report of CTW monitoring. The statistician 

will compute a point estimate and confidence interval for the percentage 

of CTWs of interest who were monitored, with “of interest” and 

“monitored” as defined above. 

SC&A assumes the purpose of the activity is to gather additional data from which 

comparisons of the relative magnitude of the available monitoring data can be done.

8. In the section, “Execution of the Sampling Plan,” NIOSH states: “The statistician will 

compute a point estimate and confidence interval for the percentage of CTWs of interest 

who were monitored, with ‘of interest’ and ‘monitored’ as defined above.” SC&A is 

concerned that such an estimate would not necessarily answer the question of whether 

unmonitored workers performed tasks side-by-side with monitored workers. While an 

estimate of the number (or percentage) of subcontractors and regular CTWs who were 

monitored internally is not without merit, the important question is whether NIOSH 

identified work plans in which unmonitored workers were performing separate tasks that 

did not include at least some monitored workers. Such an analysis is inherently more 

qualitative in nature than quantitative.

9. Attachment A of NIOSH’s sampling plan includes a description of how indexed work 

permits identify construction work, but it does not include specific instructions on 

identifying subcontractors involved in the construction work. However, SC&A assumes 

that all work permits included in the final sample will involve subcontractors in some 

capacity. This assumption is based on the definition provided for “folders of interest”: 

A folder of interest has at least one RWP (or job plan) with both RWP 

detail (header) data (indicating work performed and/or monitoring 

requirements) and sign-in sheets of workers. Sign-in sheets may also be 

used if the RWP header is denoted as available in another folder. At least 

one of those workers must be a subcontractor CTW who should have been 

monitored by bioassay. 
Memo – Comments on Draft Permit Sampling Plan 4 SC&A – April 26, 2018 

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

References

 2017. Interview (written response to questions), October 6, 2017, 

forwarded to SC&A by NIOSH via email on October 24, 2017. 

ORAUT-RPRT-0083. 2017. Evaluation of Monitoring of Construction Workers Identified in 

High-Level Cave Job Plans at the Savannah River Site, Revision 00, National Institute for 

Occupational Safety and Health, Cincinnati, OH. June 27, 2017. 

SC&A 2018. Email from SC&A, Inc. to Savannah River Site Work Group, Subject: SRS Records 

Review: 1972–1989. February 15, 2018. 

Taulbee 2018. “SRS Work Permit Sampling Plan,” attachment to email from Tim Taulbee, 

NIOSH, to Bradley Clawson, Chair, Savannah River Site Work Group, Subject: SRS Work 

Permit Evaluation – Path Forward. April 17, 2018. 
Memo – Comments on Draft Permit Sampling Plan 5 SC&A – April 26, 2018 

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

ATTACHMENT: SC&A’S POSITION REGARDING PRE-1989 PERMIT SAMPLING

In his email of April 17, 2018, transmitting NIOSH’s proposed permit sampling plan, Tim 

Taulbee indicates that, based on a survey of Radiation Survey Logsheets during the 1970s and 

1980s, the number of surveys for DuPont in-house maintenance greatly exceeded that of 

subcontractor work. As Tim noted, Joe Fitzgerald (SC&A) agrees that use of subcontractors 

during the DuPont era (before 1989) was much more limited than during the Westinghouse 

Savannah River Company (WSRC) era, and that DuPont tended to use in-house CTWs side-byside with its own employees. Regardless of the relative magnitude of subcontractor CTW use by 

the site during the 1970s and 1980s, it is still necessary to establish that those subcontractors 

were doing the same work as the in-house CTWs. It is not totally clear what specific concern is 

being conveyed here, but assuming NIOSH is questioning the value of sampling any permits 

before 1989, SC&A wants to reconfirm and add additional basis to its prior recommendation to 

the Work Group, as contained in its email of February 15, 2018 (SC&A 2018): 

As a followup to last Friday’s teleconference regarding SRS path forward, we 

have discussed this within SC&A, and propose that NIOSH pursue pre-1989 

RWPs/SWPs in terms of obtaining a representative sample from which a bioassay 

completeness assessment can be performed for that earlier period. This 

assessment would need to reflect the availability of RWPs/SWPs for 1972–1988, 

and encompass a sufficient scope of facilities and timeframe. Based on Tim’s 

presentation, it appears that 11 boxes have been identified to date that contain 

records of this kind for that period; presumably, additional boxes will be 

identified as the ongoing NIOSH review is completed. It would be important that 

NIOSH include a sampling approach for the pre-1989 period based on what is 

found in the boxes. The work group, supported by SC&A, would review these 

sampling plans (including one for the latter period) and provide any comments to 

NIOSH, as noted Friday’s call. Given the relatively fewer number of transient 

subcontractors (and subcontractors, in general) and RWPs during the 1970s 

and 1980s, it is understood that NIOSH’s sampling approach may differ from 

what is done for the 1990s. 

We believe this approach to be the most efficient one that can provide the best 

assessment on the subcontractor completeness at this point. [Emphasis added.]

In this email, SC&A again acknowledges the “relatively fewer number of transient 

subcontractors (and subcontractors, in general) and RWPs during the 1970s and 1980s” and 

understands that “NIOSH’s sampling approach may differ from what is done for the 1990s.” 

However, it should be pointed out that the number of subcontractor CTWs identified by Tim in 

his email for one SRS area, 773-A, for March 1973 (“0” subcontractors, compared with 35 

DuPont CTWs and 185 operations employees), does not comport with a later survey conducted 

by NIOSH for the same facility for 1981–1986 (as show in Table 2-2 of ORAUT-RPRT-0083, 

reproduced below). That table shows a total of 650 subcontractor CTWs at 773-A during that 

time period, with as many as 172 subCTWs in the year 1985, alone. It is clear that the particular 
Memo – Comments on Draft Permit Sampling Plan 6 SC&A – April 26, 2018 

NOTICE: This document has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 USC §552a and has been cleared for distribution. 

year and SRS facility chosen to be sampled (as least for Radiation Survey Logsheet surveys) will 

influence the number of subcontractor CTWs identified. 

For certain facilities—773-A is one example, but there are probably a few others—the number of 

subcontractor CTWs may rival DuPont CTWs (as shown in NIOSH’s Table 2-2) for some years 

and may compare with WSRC in the 1990s as well. This is not to suggest that the finding of 

fewer overall subcontractor CTWs at SRS prior to 1989 is wrong, but that supposition may not 

be universal for all facilities for all years, particularly in the 1980s leading up to an operational 

transition to decontamination and decommissioning, restart, and waste management activities.

It is important to sample what pre-1989 RWPs are available to validate that the two worker 

cohorts (DuPont CTW and subCTW) are similar in terms of work and exposure potential. This 

would add further basis for confirming that conclusion, given the initially ambiguous findings of 

the recent NIOSH/OCAS Claims Tracking System (NOCTS) comparison. This would argue for 

a sampling regime focused on the SWPs identified for A Area facilities, for which permits were 

identified in the 1972–1989 timeframe (although SWPs appear to have been phased out by 

1976). It would also argue for continued scrutiny for any additional boxes of permit records that 

may apply for pre-1989 facilities beyond just A Area.

Table 1. Total Identified Workers by Year 

(reproduced from Table 2-2 of ORAUT-RPRT-0083) 

Year DuPont CTW

DuPont CTW with 

potential for intake Subcontractor CTW

Subcontractor CTW 

with potential for 

intake

1980 60 48 [redacted] [redacted]

1981 47 41 82 47

1982 68 55 80 20

1983 70 43 99 57

1984 60 49 122 65

1985 49 44 172 115

1986 43 25 87 38

Totals 397 305 650 350